The present invention pertains to an axle suspension for rigid axles of vehicles, especially of air-cushioned utility vehicles.
Axle suspensions that contain a four-point connecting rod have been known, e.g., from DE 195 21 874 A1. The design embodiment of such axle suspensions is, in principle, simple, compact and cost-saving and has proved to be definitely successful in practice. However, this axle suspension, like other designs known from the state of the art, has the drawback that numerous components are necessary for axle guiding, which requires an increased assembly effort and also adversely affects the overall weight of the vehicle. Furthermore, prior-art axle suspensions are sometimes kinematically redundant. This in turn leads to an undefined course of kinematic processes within the axle construction in certain situations, which has an adverse effect on the coordination of the chassis or the chassis dynamics in the vertical and lateral directions under certain circumstances.
The technical object of the present invention is to improve an axle suspension such that the kinematic conditions are improved in order to optimize the dynamics of the vehicle movement. Moreover, the number of the individual components shall be further reduced.
According to the invention, an axle, suspension for rigid axles of vehicles, especially air-cushioned utility vehicles is provided with a twistable four-point connecting rod connected both above the vehicle axle to the vehicle axle and to the vehicle body via two joints each, which are arranged at spaced locations from one another in the longitudinal direction of the vehicle. At least one spring assembly unit per vehicle side is located for springing between the vehicle axle and the vehicle body. An axle strut for axle guiding extends approximately centrally of the vehicle in the longitudinal direction of the vehicle and connects the vehicle axle to the vehicle body in a vertically movable manner.
Thus, an axle suspension according to the present invention comprises a twistable four-point connecting rod, which is arranged above the vehicle axle and is connected to the vehicle axle, on the one hand, and to the vehicle body, on the ether hand, via two joints located at spaced locations from one another in the transverse direction of the vehicle.
In addition, at least one spring assembly unit is arranged between the vehicle axle and the vehicle body on each side of the vehicle.
The fact that only one axle strut, which extends in the longitudinal direction approximately in the middle of the vehicle and connects the vehicle axle to the vehicle body in a vertically movable manner, is used, can be considered to be the peculiar feature of such an axle suspension. The axle strut is arranged on the side of the vehicle axle located opposite the four-point connecting rod. The mounting of the four-point connecting rod and the axle strut in the reverse arrangement is, of course, within the scope of the present invention.
The kinematic conditions of the axle suspension are simplified and optimized by such a design. The number of components decreases considerably, so that the axle structure as a whole is less expensive than designs known hitherto.
Thus, the spring assembly units or the shock absorbers are mounted according to the present invention on longitudinal beams, which in turn have a connection to the vehicle axle, so that there is an indirect connection between the vehicle axle and the vehicle body. It has proved to be particularly advantageous for each longitudinal beam to have at least one mount for the spring assembly units. The longitudinal beams are now arranged extending on each side of the vehicle approximately in the longitudinal direction of the vehicle and may accommodate one or more spring assembly units as well as also shock absorbers if necessary. For mounting the spring assembly units and the shock absorbers, the mounts may be designed as joints, and ball-and-socket joints may also be used for this purpose according to a special embodiment of the present invention. The ball-and-socket joints have the advantage of ensuring an easily movable mounting of the corresponding assembly units, so that the pneumatic spring bellows are loaded to an extremely low extent only, e.g., in the case of the use of pneumatic springs.
The components of the vehicle body include according to the present invention at least two parallel longitudinal frames, which are connected to one another by crossbeams located at spaced locations from one another approximately in the transverse direction of the vehicle.
The axle strut for axle guiding, which extends in the longitudinal direction of the vehicle approximately in the middle of the vehicle and connects the vehicle axle to the vehicle body in a vertically movable manner, may be connected to one of the crossbeams by means of a carrier bracket in another embodiment of the present invention. Quite generally, a carrier bracket is defined as a mounting device, which accommodates a molecular joint of the axle strut, on the one hand, and is fixed to the vehicle body, on the other hand. The axle strut preferably has a molecular joint at each of its ends.
To achieve optimal springing of the vehicle axle, the spring assembly unit may be arranged in front of or behind the vehicle axle or in front or and behind the vehicle axle in an axle suspension according to the present invention.
Exemplary embodiments of the subject of the present invention will be explained in greater detail below on the basis of the drawings attached.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.